Study On Calculation Methord For Folding Steel Beam And Concrete Column Hybrid Structure Under Horizontal Load

Compared with the traditional lightweight steel construction of portal frame,the folding steel beam and concrete column hybrid structure is more and more applied to industrial plant structure due to its high strength and cost performance.Due to the late start,there are no relevant standards and specifications in China,and many designers still design the hybrid structure according to the existing frame structure or portal frame structure.At present,the research results of the stress state under vertical load of the folding steel beam and concrete column hybrid structure are presented,which indicates that the joints of the beams and columns can not reach the effect of complete rigid connection or hinge connection,and the node is a semi rigid connection which can bear a part of the bending moment.The calculation of the hybrid structure according to the existing specifications is obviously inconsistent with the actual stress conditions.Therefore,the study of the stress state of the folding steel beam and concrete column hybrid structure under the horizontal load has certain theory and engineering for perfecting the theoretical calculation of the structural form.In this paper,the semi-rigidity of beam-column joints is simulated by using helical springs in the theoretical derivation.The formulas for the internal forces at the joints of the hybrid structure under vertical and horizontal loads are deduced,and the internal forces and compares the internal force and lateral displacement of the semi rigid connection with the rigid connection and the articulated structure under the same conditions,and obtains the distribution law of the structural internal force.Based on the theoretical derivation,the factors that influence the internal force distribution of the structure are further studied to provide reference for structural design.Finally,ANSYS finite element software is applied to simulate the overall structure of the folding steel beam and concrete column,and the feasibility of the formula is verified by comparing the results of linear and nonlinear analysis.The study shows that the bending moment value of the semi rigid connection steel beam concrete column structure at the beam column joints is between the rigid connection and the articulated joints.The bending moment values at the joints also change the internal force and lateral displacement distribution of the whole structure,and the difference is larger than the internal force and displacement of the rigid connection and the articulated structure under the same condition.By comparing the results of finite element analysis,it is known that the nonlinear factors have little influence on the structural internal force distribution when the load is not more than the maximum load code,and the linear elastic hypothesis derived from the theory is feasible.The internal force distribution and lateral displacement of the structure are influenced by the shape coefficient of the wind load,the rotational stiffness of the node and the load condition,so the influence of the combination of different factors on the internal force and deformation calculation should be paid attention to in the design.